Clamps with flexible jaw members



June 20, 1961 D, J A 2,989,099

CLAMPS WITH FLEXIBLE JAW MEMBERS Filed Aug. 14, 1959 Afa E; .1. a2

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' l'c 4c v i E NTOR. 2 INVE 7o OOMl/V/C J7 DAM/VI 1-5.5 gnimad United States Patent 2,989,099 QL kMPS WITH FLEXIBLE JAW MEMBERS DOIllllllC J. Damm, Detroit, Mich, as'signor to Detroit Stamping Company, Detroit, Mich., a corporation of Michigan Filed Aug. 14, 1959, Ser. No. 833,854 3 Claims. (Cl. 144-302) This invention relates to improvements in the construction of clamps, particularly clamps of the toggle type, and provides a jaw member or members therefor having a resilient clamping action.

A clam constructed inaccordance with the invention essentially includes a jaw member which is movable by suitable means between released and clamping portions for engaging an article against a reaction member which may be another movable jaw member. The jaw member has an inner portion which is suitbly attached to the means for moving the jaw member, and an outer portion which engages the article. A blank of relatively flexible material having major and minor cross-sectional dimensions is used in forming the jaw member. For example, the blank may have a rectangular cross-section. This blank is formed so that the major cross-sectional dimension thereof lies in the plane of jaw movement along the inner portion of the jaw member and so that along the outer jaw portion the major cross-sectional dimension lies perpendicular to the plane of jaw movement. With this simple configuration, the inner portion of the jaw member becomes relatively rigid and the outer portion relatively flexible.

The invention is especially useful in the construction of toggle type of clamps, particularly clamps of this type which are designed for light duty. These clamps can be manufactured very cheaply and in a wide variety of jaw styles from the same jaw blanks as illustrated in the accompanying drawing which includes the following views:

FIGURE 1, a plan view of a toggle clamp having a pair of jaw members constructed in accordance with the invention;

FIGURES 2, 3, 4 and 5, plan views, each showing a different arrangement for the outer ends of jaw members for the clamp of FIGURE 1.

Referring to FIGURE 1, the clamp includes a pair of handles and 11 which are pivoted to each other at 12. Handle 10 is pivotally connected at 14 to a jaw member 15, handle 11 is pivotally connected at 16 to a jaw member 17, and the two jaw members and 17 are pivotally connected to each other at 18 thereby forming a conventional type of toggle construction with the toggle being shown in closed position.

Each of the jaw members 15 and 17 are made from a blank of relatively heavy sheet metal, this blank being preferably formed by stamping. Each jaw member is off-set, as indicated at 20, an amount approximately equal to the thickness of the material so that when the two jaw members 15 and 17 are placed face-to-face and connected by the pivot 18, their portions outwardly of the ofi-set will lie in the same plane. In the construction shown, each jaw member has a rectangular cross-sectional configuration, the width, or major dimension being greater than the thickness, or minor dimension. When the jaw member is formed, the blank is shaped so that the major cross-sectional dimension indicated by the arrow 22 on the inner portion 23 of the jaw member lies in the plane of jaw movement, or in other words, perpendicular to the axis of the jaw pivot 18. The outer portion 24 of each jaw member is twisted so that the minor cross-sectional dimension 26 lies in the plane of jaw movement. In FIGURE 1 the end 28 of each jaw memher is bent inwardly and provided with a curled lip 29,

the dimensioning being such that the jaw members just touch each other as shown when the clamp is closed.

The jaw construction and configuration results in the inner portion 23, including the portion around the pivots 18, and 14 or 16, being relatively rigid in the plane of jaw movement, whereas the outer jaw portion 24 is relatively flexible. The jaws are designed so that a certain jaw clamping pressure is developed when the jaws are brought into engagement with an article of a certain thickness; for example, engagement of the jaws with an article having a thickness of inch may develop a jaw pressure of 35 pounds. Such engagement is accompanied by flexing in the outer portion 24 of each jaw but this flexing is confined to this portion of the jaw and does not result in any appreciable distortion of the jaw inner portion 23. Hence operation of the toggle joint is not aliected. The jaws will obviously be selfadjusting for any minor variation in the thickness of the article engaged. Such variation in thickness will, of course, result in a change in the jaw pressure but in practically all cases, the exact jaw pressure of a clamp is not a critical factor and variation can be tolerated within reasonable limits. A clamp proportioned substantially as illustrated in FIGURE 1, can be used on articles having a thickness up to about of an inch.

FIGURES 2 through 5 give a few examples of alternate configurations for the outer portions of a pair of jaws. All of these configurations can be obtained from the same basic jaw blank, showing the adaptability of the construction in providing clamps designed for particular uses.

In the construction shown in FIGURE 2, the jaw member 15a is provided with an outer portion 24a whose end 32 extends at a right angle toward the end 33 of the opposite jaw member 17a. The clamping action of this construction will be similar to that of the construction shown in FIGURE 1.

In FIGURE 3, the jaw member 15b is provided with a relatively short outer portion 24b and a bolt 34 is mounted on this portion 24b to provide an adjustable jaw gap. The jaw member 17b is also provided with a relatively short outer portion 24b, and a curled article engaging end 35. The jaws of this construction are relatively rigid due to the short outer portions 24b of the jaws. This is desirable where an adjustable type of clamping member, such as the bolt 34 is employed.

In FIGURE 4 the jaw members 15c and 17 each have a relatively long outer portion 240 which is given a sinuous-configuration, and the jaw ends 36 and 37 are separated by a gap when in closed position as shown. The sinuous configuration gives greater relative flexibility to the jaw ends 36 and 37, and also provides a second pair of clamping points 38 and 39', which are separated by a slightly greater gap so as to develop a clamping pressure approximately equal to that developed at the jaw ends for the same article thickness.

In FIGURE 5, the jaw member 17d has its outer portion 24d formed similarly to the jaw 17a of FIGURE 2. The opposite jaw member 15d has its outer portion 24d formed to extend first parallel, then in gradually converging relation to the opposite jaw and terminating in an article engaging part 49 which is spaced from the curled article engaging end 41 of the opposite jaw. This configuration increases the rigidity of the jaw and also illustrates one way in which the jaws can be formed to accommodate articles of greater thickness.

While preferred embodiments have been described above in detail, it will be understood that numerous modifications might be resorted to without departing from the scope of the invention as defined in the following claims.

I claim:

1. A clamp of the toggle type having a pair of jaw members which are pivotally interconnected and each pivotally connected to one of a pair of pivotally interconnected handles for movement from an open position to a closed position in which the spacing normal'between said jaws is fixed, characterized by means for providing compensation for variation in the thickness of an article engaged by said jaws comprising at least one of said pair of jaw members being formed from a blank of relatively flexible sheet material, said blank having major and minor cross-sectional dimensions along the length of said jaw member, said jaw member having outer and inner parts with the length of said outer part being at least equal to the length of said inner part from said pivotal inter-connection to said outer part, said outer part including an integral article engaging portion and being formed with said minor cross-sectional dimension extending in the plane of jaw movement, said inner jaw part having said major cross-sectional dimension extending in the plane of jaw movement whereby said inner jaw part is relatively rigid and said outer jaw part flexible relative to said inner part to permit relative movement between said article engaging portions of said one jaw and the other of said pair of jaws on engagement with an article having a thickness greater than said normal spacing.

2. A clamp as set forth in claim 1 further characterized by the other of said pair of jaw members being formed similar to said one jaw member and including outer and inner parts, saidouter part having an integral article engaging portion formed thereon, said outer part being flexible relative to said inner part to permit relative movement between the article engaging portions of said pair of jaws in theclosed position thereof.

3. A clamp according to claim 2 further characterized by said pair of jawshaving a second pair of article engaging portions integrally formed on the said outer part of each, said second pair of article engaging portions being located inwardly of the first mentioned article engaging portions and being separated by an amount greater than said normal spacing between the said first mentioned article engaging portions when said jaws are in closed position whereby an article can be simultaneously engaged by both article engaging portions of each of said jaws with substantially equal jaw pressure.

References Cited in the file of this patent UNITED STATES PATENTS 89 1,061 Hansen June 16, 1908 942,356 Shelley Dec. 7, 1909 1,277,946 Kenkel Sept. 3, 1918 1,428,679 Caswell Sept. 12, 1922 2,327,368 Olson Aug. '24, 1943 2,367,552 Ahrndt Jan. 16, 1945 2,456,100 Wood Dec. 14, 1948 2,502,804 Spencer Apr. 4, 1950 2,565,750 Bertino Aug. 28, 1951 

